As optical recording media, optical disks such as a Digital Versatile Discs (DVDs) and Blu-ray Discs (BDs) are conventionally known. Such optical recording media are formed to enable reproduction of information or both reproduction and recording of information. In regard to the optical recording media, there is known a technology that enhances recording density in a recording layer through realization of short laser wavelength, high objective lens numerical aperture, use of a recording medium material suitable for high-density recording, countermeasures against noise in reproduction signal processing, and other features.
Further, as a technology that enhances the recording density, there is known a multilayer optical recording medium in which multiple guide layers and multiple recording layers are provided or a drive device that performs, for example, recording or reproduction using this multilayer optical recording medium.
However, the multilayer optical recording medium may be warped by internal stress due to an environmental change such as a temperature and humidity or age deterioration in some cases. When warpage occurs, functions of the multilayer optical recording medium may possibly be lost and, for example, a non-recorded region may be generated or a recorded region may be overwritten.